This invention relates to an assembly and method for installing a pipe liner within a sewer pipe, and specifically to an assembly and method for installing a pipe liner within a branch line of a sewer pipe.
Typically, a sewer pipe includes a main line which extends substantially parallel to a street or road. Residents or buildings include branch lines that extend from the building to the main line. Conventional repair of sewer pipes includes digging the pipes up and replacing the damaged areas. Often times it is undesirable to dig a hole to obtain access to the sewer pipes. Further, digging a hole to gain access to sewer pipes is expensive, unsightly, and very undesirable along with being time consuming.
It is known in the art to reline sewer pipes in place through access holes such as manholes. The relining in place process includes a resin impregnable liner installed within the tube and held in place until hardened. The resin impregnable liner becomes a new pipe installed within the old pipe. This method of repair is essentially transparent to residents, meaning that the surrounding area is not disturbed or dug up. The relining process includes the use of an inflatable bladder along with the resin impregnable pipe liner which inserts within the sewer pipe. The bladder tube inflates to drive the resin impregnable pipe liner outward against the inner surface of the sewer pipe. The bladder tube remains inflated in place until the resin impregnable pipe liner hardens.
Typically, the lining of a branch pipe is best performed from a point within the main sewer pipe. A known device for installing a lateral line from a main line includes a carrier assembly designed for use with a t-shaped bladder assembly. The t-shaped bladder assembly includes a first portion that inflates within the main sewer and a second portion that extends from the first portion into the branch pipe. The pipe liner assembly is also t-shaped, and includes a main line section and a branch section. The main line section forms a sectional liner within the main sewer pipe and the branch section extends from the main section into the branch pipe. This device requires that the main line section of the bladder assembly be inflated before the branch section of the liner will extend into the branch pipe.
In some instances, the main line bladder portion includes a relatively large unsupported area. The unsupported area is not in contact with the inner surface of the main line or the outer surface of the carrier. The unsupported surface is especially susceptible to rupture under certain circumstances. As appreciated, if the bladder assembly bursts during installation, and before the pipe, liner has been fully extended within the branch line pipe, the resin impregnable liner will harden in a crumpled condition within the branch pipe. Such a condition requires remedial action by the contractor installing the pipe liner. Remedial action includes digging up the pipe and removing the uninverted pipe liner and installation equipment.
Accordingly, it is desirable to develop an assembly and method for installing within a resin impregnable pipe liner within a branch line that is reliable and supports substantially all of the bladder assembly.
An embodiment of this invention is a launcher assembly including an inflatable member actuatable between inflated and deflated conditions to secure the launcher, pipe liner and bladder assembly within a branch line pipe.
The launcher includes a retainer and guide connected by a body portion to define a passage through which the bladder and pipe liner pass from a main line sewer pipe to a branch line sewer pipe. The inflatable member is attached to the retainer and has an outer diameter sized to cooperate with an inner surface of a branch line pipe. The guide connects to a carrier tube through which the pipe liner and bladder are passed. The launcher includes an air hose in communication with a cavity of the inflatable member that provides for the actuation of the inflatable member between inflated and deflated conditions.
The body of the launcher is configured to fit within the main pipe. The retainer extends transversely from the body at a predetermined angle for pivoting of the launcher within the main pipe up into the branch line pipe. The launcher includes a height measured from a bottom portion of the body to the top most portion of the retainer. This height is configurable to allow the launcher to fit within a specific main line pipe.
The guide of the launcher includes a quick connection feature that cooperates with the carrier tube allowing a single carrier tube to be used with many different configurations of the launcher. The height of the launcher and the diameter of the retainer are configured to allow installation of a pipe liner within many known branch and main line sewer pipe configurations.
In operation, the bladder tube is inserted through the passageway defined by the launcher and cuffed over the outer diameter of the inflatable member. The cuffed end of the bladder tube is secured to the retainer by a band clamp. The pipe liner is then extended from within the bladder tube and cuffed over the bladder tube disposed on the outer diameter of the inflatable member. The launcher is then lifted into the branch pipe, where the inflatable member is actuated to the inflated position to secure an end of the bladder and pipe liner against an inner surface of the branch pipe. Note that the bladder tube is secured in place mainly by the clamp with the additional securing force exerted by the inflatable member. The inflatable member inflates to trap the bladder and pipe liner against the inner surface of the branch pipe. Air pressure applied to the bladder tube drives the bladder tube and pipe liner into the branch pipe.
Branch pipes are often not configured perpendicular to the main line pipe. Another embodiment of this invention includes a pivotal connection between the retainer and guide portion to allow for adjustment of the angle of the launcher for use in branch line pipes that connect to the main line sewer pipes at angles other than 90xc2x0. In this embodiment, the retainer portion and guide portion define a passageway through which the pipe liner and bladder assembly pass during the installation process. Between the retainer and guide is a body tube. The body tube is a flexible tube providing an airtight connection between the retainer and guide that protects the pipe liner and bladder assembly as they pass through the launcher.
The launcher of this embodiment includes an insert that seats within the retainer and includes an insert arm. The insert arm extends from the retainer and attaches to a pivot arm. The point of attachment between the insert arm and the pivot arm is adjustable to adapt to branch line pipes of different angles. Further, the pivot arm attaches to the guide by way of a fastener disposed within a slot. The slot of the pivot arm provides for movement of the retainer relative to the guide during installation of the launcher into a branch line pipe. The pivotal connection between the insert arm and the pivot arm along with the pivotal connection between the pivot arm and the guide allows for some movement of the launcher during installation into the branch line pipe.
This invention also includes a method of installing a pipe liner within a branch liner pipe. The method includes the steps of first clamping a bladder tube assembly to an outer diameter of a retainer portion of the launcher assembly. Installing a pipe liner to the outer diameter of the retainer portion to the outside of the previously installed bladder tube assembly. The method further includes the step of inserting the launcher into the branch line to a point where the inflatable member is substantially within the branch line. The inflatable member is inflated to trap the bladder tube and pipe liner assembly between the retainer and the inner surface of the branch line sewer pipe. Note that although the inflatable member traps the bladder tube, the bladder tube secured to the retainer by way of clamps to create a reliable airtight seal. Air pressure drives the bladder assembly forward of the launcher assembly into the branched line pipe. The bladder assembly remains in place to hold the pipe liner against the inner surface of the branch line pipe until the pipe liner has fully hardened. Once the bladder assembly is inflated, the inflatable member is deflated. The launcher remains in place until the pipe liner hardens. The bladder assembly is then deflated and pulled from the branch line. The pipe liner remains in the branch line pipe to form a new inner surface.
The launcher assembly of this invention provides a simple and reliable method of installing a resin impregnable pipe liner within a branch line pipe that prevents rupture by supporting substantially all of the bladder tube.